The eShunt™ System is a minimally invasive method of treating communicating hydrocephalus. The eShunt System includes a proprietary eShunt Delivery System and the eShunt Implant, a permanent implant deployed in a minimally invasive, neuro-interventional procedure. The eShunt Implant is designed to drain excess cerebrospinal fluid (CSF) from the intracranial subarachnoid space (SAS) into the venous system.

This is a prospective, single-center, open label, single-arm pilot study of the eShunt System. The study population consists of patients with post-aneurysmal subarachnoid hemorrhage (SAH) treated for increased intracranial pressure (ICP) resulting in symptomatic hydrocephalus using an external ventricular drain (EVD) to facilitate CSF drainage and who cannot be "weaned" from the EVD following the hemorrhagic event.

The study will be performed a single site with up to 30 subjects who meet the inclusion and exclusion criteria for the study. Subjects will be evaluated every 30 days for the first 90 days following eShunt Implant deployment with standard neurological evaluation appropriate for patients with communicating hydrocephalus. In addition, follow-up will occur at 180 days, 12 and 24 months post-operatively and will include imaging in addition to the standard neurological evaluation.

Inclusion Criteria:

1. Age > 18

2. Subject provides Informed Consent (IC)

3. Post-aneurysmal SAH with Hunt and Hess Grades I-IV with EVD in place with the need for a permanent CSF shunt determined through a failed EVD clamping trial defined as:

   1. Post-clamping ICP of > 20 cmH2O for 15 min, or
   2. Post-clamping ICP > 25 cmH2O for < 15 min with patient intolerance to EVD clamping
   3. Post-clamping ICP >15 cmH2O for 15 min with radiographic evidence of ventriculomegaly

4. Clinical signs and symptoms of communicating hydrocephalus

5. Neurologically stable without evidence of severe vasospasm

6. Pre-procedure MRI with gadolinium confirmation of IPS (inferior petrosal sinus) and CPA (cerebellopontine angle) cistern anatomy suitable for eShunt Implant deployment as confirmed by SSC (subject screening committee)

7. Pre-procedure CT confirmation of no obstruction preventing CPA cistern access at target implant site (e.g., petrous bone) as confirmed by SSC

Exclusion Criteria:

1. Patient is in a state of unconsciousness or is unable to understand the information provided in the Informed Consent Form for this study
2. Indication of obstructive hydrocephalus
3. Presence of gross blood in CSF from EVD
4. Pregnant
5. Unwilling or unable to comply with follow up requirements
6. Active systemic infection or infection detected in CSF
7. Life expectancy < 1 year
8. Hypersensitivity or contraindication to heparin or radiographic contrast agents which cannot be adequately pre-medicated, desensitized or where no alternative is available
9. Occlusion or stenosis of the internal jugular vein
10. Venous distension in the neck on physical exam
11. Atrial septal defect or patent foramen ovale identified on cardiac echocardiogram
12. History of bleeding diatheses, coagulopathy or will refuse blood transfusion in cases of emergency
13. Clearly antecedent stroke unrelated to post-aneurysmal SAH
14. Patient is currently participating in another investigational drug or device trial that could conflict with study data collection or follow-up
15. Other medical illnesses that may cause the patient to be non-compliant with the protocol or confound data interpretation as determined by the study Investigator
16. Presence of a deep vein thrombosis superior to the popliteal segment of the femoral vein
17. International Normalized Ratio (INR) or Partial Thromboplastin Time (PTT) results outside of normal range (INR 0.8-1.4; PTT 25-35 secs.)